Postecoglou has never been one to stick by a settled first team.
In his 48 matches in charge of the national team, the Socceroos coach has selected an unchanged side once - between the semi-final and final of the 2015 AFC Asian Cup.
And tonight's World Cup qualifying showdown with Honduras won't be the second.
It's not because Saturday's (AEDT) performance in San Pedro Sula wasn't meritorious.
Even Postecoglou's critics have praised the Socceroos' showing in Honduras, where Australia was unlucky not to score in a 0-0 draw.
It's because Postecoglou believes in constant change, a mantra that constantly embarrasses those trying to predict his starting team.
The biggest selection factor for the ANZ Stadium clash is fitness, and how the starting XI have pulled up from the terrible pitch from the first leg.
Here are the candidates for the second leg in Sydney.
Who's in line for the Socceroos showdown?
Mat Ryan is clearly the first-choice and it would astonishing to see Mitchell Langerak in between the sticks.
Trent Sainsbury is the central figure and should continue.
Matt Jurman has come from the clouds for the play-offs against Syria and Honduras, but has barely put a foot wrong - can Postecoglou really drop him?
Milos Degenek will contend strongly to replace Bailey Wright after Postecoglou admitted he was kept on ice in Honduras as a possible replacement for Josh Risdon.
Mark Milligan could also slot into the back three depending on the midfield make-up.
Available-again Postecoglou favourite Mat Leckie will come in for Risdon if he's overcome a groin complaint.
Aziz Behich's showing on the left could earn him another cap but don't be surprised if the coach opts for 20-year-old Alex Gersbach.
Fitness should be the only query over skipper Mile Jedinak, who was immense in Honduras while playing his first full match in five months. Otherwise it's Milligan to the rescue.
Here lies Postecoglou's biggest dilemmas. The trio of Massimo Luongo, Aaron Mooy and Jackson Irvine worked wonders in Honduras, but Milligan and Tom Rogic will present strong claims for inclusion.
Rogic is surely a starter, most likely for Irvine.
Could Australia's player of the year, Mooy, be dropped again? If his dead ball use was stronger in Honduras, he'd be impossible to deny.
Robbie Kruse and James Troisi also have claims to start as a number 10 but fitness and form respectively might keep them on the bench.
Tim Cahill or Tomi Juric? Juric regularly wins this selection battle but Cahill has shown himself to be the man for the big occasion so many times over the journey - not least in Australia's 2-1 win over Syria.
Both will certainly see game time. Nikita Rukavytsya could also enter the equation late in the game.